1. Field of the Invention
This invention relates in general to the construction of bearing assemblies and in particular to a new and useful bearing socket construction for connecting particularly movable beam type trucks to the body of railroad vehicles.
2. Description of the Prior Art
The present invention is particularly concerned with the construction of bearing sockets which are used for the undercarriages of high speed rail vehicles. In such an assembly the cup or cup shaped parts of the bearing socket engage each other horizontally in frictional contact and they form an exact horizontal guide for the movable beam of the truck which is suspended for swinging or oscillation from the frame of the truck. In such a bearing socket construction it is well known to provide a flat disc of plastic or felt or similar material which is received between the horizontal surfaces of the bearing socket parts. Such a disc serves for the purpose of reducing the wear reducing the coefficient of friction, and providing an anti-seizure lubrication. A disadvantage of the known construction is the relatively short life of the disc and the transmission of the riding noise of the truck to the car body as well as the cost of maintenance of the bearing socket.
A known design of a spherical bearing socket for a railroad freight car includes a disc shaped rubber metal intermediate body which is inserted between the parts of the socket. The rubber metal insert comprises one or a plurality of layers of rubber and on the outside or inside sheet metal shells are vulcanized to the rubber. Such a rubber metal insert is placed loosely between the lower and the upper parts of the bearing socket. The cross-section of the rubber portions increases from the axis of the bearing socket toward the outside in order to absorb the longer travel necessarily covered at the outside during a rotational movement of the bearing socket by an inner deformation. In such a design it is disadvantageous that the relatively large cross-section of the rubber prevents an accurate guidance of the truck by the bearing socket. For this reason the design cannot be applied to a bearing socket of this type.